#!/bin/bash

sudo cp /etc/apt/sources.list /etc/apt/sources.list.bak
echo "# 默认注释了源码镜像以提高 apt update 速度，如有需要可自行取消注释                                                                    " > /etc/apt/sources.list
echo "deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal main restricted universe multiverse                  " >> /etc/apt/sources.list
echo "# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal main restricted universe multiverse            " >> /etc/apt/sources.list
echo "deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-updates main restricted universe multiverse          " >> /etc/apt/sources.list
echo "# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-updates main restricted universe multiverse    " >> /etc/apt/sources.list
echo "deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-backports main restricted universe multiverse        " >> /etc/apt/sources.list
echo "# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-backports main restricted universe multiverse  " >> /etc/apt/sources.list
echo "deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-security main restricted universe multiverse         " >> /etc/apt/sources.list
echo "# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-security main restricted universe multiverse   " >> /etc/apt/sources.list
echo "                                                                                                            " >> /etc/apt/sources.list
echo "# 预发布软件源，不建议启用                                                                                              " >> /etc/apt/sources.list
echo "# deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-proposed main restricted universe multiverse       " >> /etc/apt/sources.list
echo "# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-proposed main restricted universe multiverse   " >> /etc/apt/sources.list